Cold Sores (Herpes Simplex Type 1)

Cold sores (fever blisters) are small, painful, fluid-filled blisters. They occur most often on the lips. These blisters may also occur in other places such as the mouth, nose, chin, cheeks, and throat, or other areas of the skin. Cold sores are often caused by the herpes simplex type 1 virus (HSV-1). Less often, however, they can be caused by herpes simplex type 2 (HSV-2). HSV-2 is the virus that most often causes genital herpes . Having a herpes simplex virus (HSV) infection around the mouth is very common. In fact, nine out of ten older adults have been exposed to HSV. Not everyone who is exposed to the virus will develop cold sores.

The virus is spread through contact with fluid from active cold sores. It may happen:

Through kissing and other close contact

Through sharing eating utensils, razors, towels, or other personal items

Sharing food or drink

Contact with saliva containing HSV

When HSV gets on the skin around the mouth, it invades nerves in the area. It then remains there quietly, for 2-20 days. Then the first outbreak may occur. This outbreak can cause blistering across the lips, tongue, and inside of the mouth. You may also have a body-wide, flu-like illness. It can occur with fever, general aches and pains, and swollen lymph glands.

The outbreak will last about 7-10 days. The virus then goes back into the nerves. It will remain there quietly until it is reactivated. This will cause a second outbreak. This outbreak will cause painful, blistering sores. They occur most often at the border of the colored part of the lip. These sores can last for up to 14 days. It is impossible to predict when these outbreaks may recur. Typically stress or illness may bring them on. They may also be brought on by sunlight, immune suppressants, or a woman's menstrual period. Some people have outbreaks regularly, while some never have another.

Cold sores have very recognizable features. They are most often diagnosed by physical exam and by your medical history. If your doctor is not sure, a sample of the fluid or tissue from the blister may be taken. A blood sample may also be taken for testing.

Testing may include any of the following:

Viral culture—A sample of the fluid from the cold sore blisters is taken with a cotton swab. This is done as soon as possible after an outbreak begins. The virus is then grown in the laboratory. This test is very accurate if the sample is taken while there are still clear blisters.

Tzanck test—The cold sore is lightly scraped to collect cells onto a glass slide. These cells are then examined under a microscope. This test is quick, but not as accurate.

Tests to detect the presence of antibodies in your blood. These particular antibodies are created by your body to fight HSV infections. Tests to look for HSV in fluid may also be done to help confirm an infection.

In her own words: living with cold sores

As told to Debra Wood, RN

Marie is a 30-year-old freelance writer who's had recurring cold sores since her teenage years. Now that she knows when to expect them, and what she can do to minimize them, they are less of a concern.

What was your first sign that something was wrong? What symptoms did you experience?

I started getting cold sores in high school. At least once every winter, I would get a sore on my nose or the area just under my nose above my lip. Before the sore showed up, I'd feel tingling in the area and the glands under my chin would feel swollen and tender. I would often have mild cold symptoms, as well, as if I was fighting something off.

The sore itself would first look like a red pimple, but then get larger and eventually turn to a scab before it healed. Sometimes, my whole nose would be red and swollen. The cold sore would last from 7-10 days. Sometimes, it would leave a temporary red scar that would last for another couple weeks.

What was the diagnosis experience like?

The diagnosis was pretty simple. My doctor took one look at the sores and knew what they were right away.

What was your initial and then longer-term reaction to the diagnosis?

I didn't have much of a reaction to the actual diagnosis, but the occurrence of the cold sores was very upsetting. I was embarrassed to go to school with a sore on my nose. And the sores seemed to show up at the worst times, like senior class photo day (this happened in both high school and college, luckily I was able to retake the photos). I would keep my head down or try to cover the sores with makeup so people wouldn't see. (The makeup was a very bad idea, it actually accentuates the sore.)

As I've gotten older, the sores occur less often and I can usually catch them and treat them before they get too bad. Also, I realize it's not such a big deal. It'll go away within a week or so.

How do you manage cold sores?

I tried all sorts of creams on the sores to make them go away faster, but nothing worked. Finally, just a few years ago, my dentist told me about an antiviral drug (acyclovir) that can help shorten the duration of the sore. The trick is to start taking the drug as soon as I feel the tingling, before the sore even shows up. I've done this a couple of times and successfully prevented the full blown sore. However, one snuck up on me recently; I didn't have time to get the prescription, so I had to just wait it out. To avoid that happening again, I'm going to fill the prescription so I'll have the pills and can start taking them immediately when I need to.

Have you made any lifestyle or dietary changes in response to your cold sores?

I have noticed that the cold sores sometimes occur when I'm feeling overtired, stressed, or when a cold is coming on. So when I start to feel these symptoms, I try to get more sleep and deal with whatever is causing the stress. Sometimes this works, sometimes it doesn't.

What advice would you give to anyone living with cold sores?

Ask your doctor for a prescription for an antiviral drug, and keep one course of it on-hand. Pay attention to your body, and take care of yourself when you are getting overtired or stressed. Also, be aware of the tingling; as soon as you feel it, treat it.

And when you're not able to prevent a sore, which will certainly happen, put it in perspective. It'll be gone in seven to ten days and you'll be fine. Try not to let it get you down too much. (This is much easier to do when you're not in high school.)

Interviews were conducted in the past and may not reflect current standards and practices in medicine. Talk to your doctor to learn more about how this condition is diagnosed and managed today and what treatment approaches are right for you.

The best way to reduce your risk of cold sore is to avoid an infection with herpes simplex virus (HSV). Unfortunately, most people are infected by the virus when they are children. Once you have HSV, it cannot be cured. You can lower the risk of recurrent cold sores by changing some lifestyle activities.

Here are some tips to reduce your risk of getting an HSV infection or having recurrent outbreaks of cold sores:

HSV can be spread by close contact with someone who has a cold sore. It can also spread by their sharing personal items such as towels, razors, or eating utensils. Do not kiss, have close contact with, or share personal items with someone who has an active cold sore. This also applies with someone who thinks they are about to have a cold sore. HSV can also spread to the genital area by having oral sex. Do not let a partner with an active cold sore perform oral sex on you.

Avoid Excessive Exposure to the Sun

Exposure to sunlight is known to cause outbreaks of cold sores. It is impossible to avoid all sun exposure but you can reduce the sun's effect. Use sunscreen on your lips and skin. Also, whenever you go outside in sunny weather, wear a large-brimmed hat. This will help to protect your face from the ultraviolet rays.

Reduce Physical and Emotional Stress

Physical and emotional stress may reduce the body’s ability to fight HSV. Stress can also trigger an outbreak of cold sores.

Exercise can help to reduce emotional stress. However, excessive exercise can weaken the body. Relaxation techniques , such as meditation and deep breathing, can help reduce emotional stress.

Practice Good HygieneHabits

Good hygiene can prevent the spread of cold sores. It may also help to reduce the length and severity of the outbreaks. During an outbreak:

Avoid touching the sores, especially avoid contact with any open cuts on your skin.

Wash your hands often during the day.

Keep your fingernails clean by scrubbing daily.

Take care not to spread the virus to other parts of your body such as the eyes and genital area.

Get Adequate Sleep and Eat a Healthful Diet

The body heals fastest when it receives rest and good nutrition. Strive for a good night’s sleep. Eat a balanced, healthful diet .

Description of Services Provided:This site provides education, support groups, and a physician locator. The information is comprehensive and contains color photos of cold sores at different stages of infection.

Description of Services Provided:This organization provides succinct, easy-to-understand information on oral and other forms of herpes. Its website contains large color photos of people with typical cold sores at different stages of the infection.

Description of Services Provided:This Canadian website, written by dermatologists, provides over 10 articles about cold sores. You'll also find a dermatology glossary and images.

Last reviewed September 2012 by Brian Randall

Last updated Updated: 09/11/2012

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

A risk factor is something that increases your likelihood of getting a disease or condition.

It is possible to develop cold sores with or without the risk factors listed below. However, the more risk factors you have, the greater your likelihood of developing cold sores.

The viruses that cause cold sores are easily spread. They come out of the skin and are “shed” from the site of the cold sore for 1-2 days before the sore appears. Then the virus is in the fluid of the cold sore blisters.

Most cold sores form because of stress or illness. Some may form without an identifiable trigger.

Risk Factors for Becoming Infected With Herpes Simplex 1 Virus

Exposure to Someone With Cold Sores

Herpes simplex virus type 1 (HSV-1) can be spread by close contact with someone who has a cold sore. It can also be spread through personal items that are contaminated with the virus such as razors, towels, or eating utensils. Kissing or sharing personal items with a person who has a cold sore will increase your risk of getting HSV-1. The virus you have can also be spread to the genital area during oral sex. People with cold sores should not perform oral sex on their partners.

Age

Infants and young children (up to three years old) have an increased risk of being exposed to HSV-1.

Risk Factors for Developing Cold Sores

Exposure to Sunlight

Exposure to sunlight or other ultraviolet light is a common trigger for cold sores.

Physical Stress and Illness

Stress on the body due to illness or excessive exercise can weaken the body’s immune system. This can lead to an outbreak of cold sores. Common examples of stress or illness include:

Medication (such as steroids) or illness (such as HIV ) that suppresses the immune system

Excessive exercise

Emotional Stress

Cold sore outbreaks commonly occur during times of emotional stress. The type of stress that activates cold sores is typically negative stress, instead of stress due to positive or normal life-changing events.

The purpose of screening is early diagnosis and treatment. Screening tests are usually given to people without current symptoms, but who may be at high risk for certain diseases.

Screening Guidelines

There are no screening guidelines for cold sores.

A simple antibody blood test can show if you have been exposed to the herpes virus in the past. If you test positive, it means you could get a cold sore in the future. However, most people test positive for herpes simplex type 1. Therefore, this test is not very useful for screening purposes.

The first exposure to herpes simplex 1 virus may result in a blistering rash in the mouth and/or lips that with a body-wide, flu-like illness. This first outbreak of cold sores is usually gone within 7-10 days, but it can last up to 20 days. The sores can also develop in other locations on the skin.

After these initial symptoms, the virus may lie quietly in the nerves until it is reactivated. This may happen due to stress or illness. Direct sunlight, a weakened immune system, and menstruation can also trigger reactivation. If reactivated, the virus will come out as a cold sore (fever blister). A few days before the sore appears, you may notice some itching, burning, or pain in the area. Some people have outbreaks regularly. Some never have another symptom after the initial infection.

The symptoms of an active cold sore are:

Small, painful, fluid-filled, red-rimmed blisters

After a few days, the blisters dry and form a scab

Scabs heal in about five days, usually without scarring or loss of sensation

You have a unique medical history. Therefore, it is essential to talk with your doctor about your personal risk factors and/or experience with cold sores. By talking openly and regularly with your doctor, you can take an active role in your care.

General Tips for Gathering Information

Here are some tips that will make it easier for you to talk to your doctor:

Bring someone else with you. It helps to have another person hear what is said and think of questions to ask.

Write out your questions ahead of time, so you don't forget them.

Write down the answers you get, and make sure you understand what you are hearing. Ask for clarification, if necessary.

Don't be afraid to ask your questions or ask where you can find more information about what you are discussing. You have a right to know.

Specific Questions to Ask Your doctor

About Cold Sores

What causes cold sores?

What are the symptoms of cold sores?

How long do they last?

How are cold sores diagnosed?

Are there any serious complications of herpes simplex that I should be aware of?

About Your Risk for Developing Cold Sores

Am I at risk for cold sores?

How do I know if someone in my family had or has cold sores? What physical signs or symptoms should I be looking for?

When are people with cold sores most contagious? Who is most vulnerable to catching herpes simplex from me?

How do I best prevent cold sores?

About Treatment Options

What is the best treatment option for cold sores?

Can they be cured?

What medications are available to help me?

What are the benefits/side effects of these medications?

Will these medications interact with other medications, over-the-counter products, or dietary or herbal supplements I am already taking for other conditions?

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY.
Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.